Compact active mixer combines up to four line level sources and provides line level output. Input CH1 and CH2 have dual mono summed RCA female inputs. Input CH3 accepts either dual mono summed RCA, or 1/4" mono input. Input CH4 accepts 1/4" mono input. Outputs include dual mono RCA line level, and 1/4" mono which may be used as line level or headphone. Each input channel has its own independent level control.